Facilities
Large-scale facilities

BEAR/SEAL

General informations

Location
Trieste, Elettra Synchrotron light source
Main techniques and methods
Reflectivity (specular, diffuse and dichroic – structural and magnetic), absorption (in transmission, total and partial electron yield, Auger yield, photon fluorescence and luminescence yield, circular and linear dichroism), photoemission (UPS, XPS, angle resolved), Auger spectroscopy, Fluorescence spectroscopy, XEOL (X-ray Excited Optical Luminescence ) and conventional lab luminescence, Metastable deexcitation spectroscopy, Electron Energy Loss spectroscopy.
Key instumentation
IOM-CNR synchrotron BEAR synchrotron beamline (3-1600 eV) (Elettra, Trieste, Italy) and relative end stations including UHV scattering chamber and surface science preparation chamber together with ancillary exits, Laboratory of Physics of Materials and Surfaces (Dip.Ing.E.Ferrari, Università Modena e Reggio Emilia) with UHV electron spectroscopy equipments.

BEAR is part of a joint research unit - SEAL (Scattering Emission Absorption Lab) dedicated to optical and electronic properties of surfaces, interfaces and thin films.

BEAR (Bending Magnet for Absorption and Reflectivity) is part of a joint research unit - SEAL – participated by personnel from IOM Headquarters and University of Modena and Reggio Emilia dedicated to the study of the optical and electronic properties of surfaces, interfaces and thin films.   

Technical description

BEAR offers photon-in and photon-out, photon-in electron-out and electron scattering spectroscopies in a UHV environment. Excitation sources include photon sources (synchrotron with control of polarization state from linear to elliptical and variable s(TE)/p(TM) polarization incidence ratio, polarized UV lamp/He and X-ray source/Mg/Al, low energy sources in the Vis-UV range – Tungsten-Deuterium lamp, LED high intensity diodes 285-533 nm), ion and electron guns. A Photo Elastic Modulator is available. Experimental station are provided with Surface science class chambers for samples preparation (annealing, ion sputtering, scraping) and thin films depositions. Remote operation (of the BEAR beamline) is available.

Development of new methods, instrumentation, software

Instrumentation: Dealing with photosensitive sample and with induced changes due to photon beam during measurement constitute a delicate aspect in photon-in spectroscopy. At BEAR beamline the problem has been faced at first evaluating and controlling the impinging power density vs energy, geometry and by an acquisition protocol  whit selection of exposure time with possibility of acquiring at selected fresh sample regions

Polarized light and related phenomena: a secondary light exit of BEAR is equipped with a photo-elastic modulator to produce circular polarized light UV and concurrently a piezo-dichroic device based on LiF crystal is considered for polarimetric observation of sun corona.

Software: Physical ray tracing: the transport and monochromatization process of BEAR optics from source to sample has been analytically described developing a code written in Mathematica allowing to get the electromagnetic field (amplitude and phase) at the focal point.

Development of a code (OPAL – Optical Properties of Anisotropic Layers) for the simulation of the optical properties of anisotropic layered materials.

 

Research Activity

the BEAR/SEAL group's activity includes:

Organic thin films and related interfaces for OTFT, OLED, OLET, photovoltaics: characterization at nano- and micro-scale (through UPS, XPS, dichroic XAS and reflectivity) to model and optimize device performance.

Morphology, local atomic order and electronic properties and related simulations codes: currently addressed topics include chemisorption geometry of organic molecules at surfaces and their interfaces, thin film magnetic dichroism, atomic geometry evolution (NEXAFS) upon lithiation in nanostructured Li-ion electrodes based on carbon-coated spinel ferrites and nanowires coatings (XEOL).

Low electron energy driven chemistry: focus on the role of low energy tail of electron cascade associated to photo-electrons in the activation of chemical reaction. Attention is currently devoted to the solubility switch of protected polymers in photoresist blends of interest in photolithography at 13.5 nm.

Study of formation of C growth under synchrotron beam (R specular and diffuse, XAS, AES, XPS) on most currently used substrates (eg Pt, Au) and on microscopic study and monitoring of C removal in UV light excited gas environment.

Luminescence for the study of skin cancer alterations.

Projects

FAR, Lumina, 2019-2022

AHEAD2020, BABE

Main collaborations

  • IMEM-CNR, Trento, Italy
  • INAF-OATO, Torino, Italy
  • Dipartimenti di Fisica, Univ. of Camerino, Italy
  • Dipartimenti di Fisica, Univ. of Roma3, Italy
  • Dipartimento di Fisica e Chimica E.Segrè Univ.Palermo and INAF- OAPA, Palermo, Italy
  • IMEC, Leuven, Belgium
  • Consejo Superior de Investigaciones Cientìficas, Madrid, Spain
  • F. Ioffe Institute, St. Petersburg, Russia
  • Institute d’Optique-Lab.Charles Fabry, Palaiseau, France
  • Laboratoire de Chemi Physique Matière-Rayonnement, Paris, France

Key publications

Small Methods, 4-10, 2020 doi:10.1002/smtd.202000617

Exchange Interactions Drive Supramolecular Chiral Induction in Polyaniline

Mishra S., Kumar A., Venkatesan M., Pigani L., Pasquali L., Fontanesi C.
Condensed Matter, 4-1:1-8, 2019 doi:10.3390/condmat4010004

Substrate-induced proximity effect in superconducting niobium nanofilms

Rezvani S.J., Perali A., Fretto M., De Leo N., Flammia L., Milošević M., Nannarone S., Pinto N.
ACS Applied Materials and Interfaces, 10-40:34392-34400, 2018 doi:10.1021/acsami.8b12596

Versatile and Scalable Strategy to Grow Sol-Gel Derived 2H-MoS2 Thin Films with Superior Electronic Properties: A Memristive Case

Nardi M.V., Timpel M., Ligorio G., Zorn Morales N., Chiappini A., Toccoli T., Verucchi R., Ceccato R., Pasquali L., List-Kratochvil E.J.W., Quaranta A., Dirè S.
Applied Physics Letters, 112-3, 2018 doi:10.1063/1.5008941

3D reconstruction of pentacene structural organization in top-contact OTFTs via resonant soft X-ray reflectivity

Capelli R., Nardi M.V., Toccoli T., Verucchi R., Dinelli F., Gelsomini C., Koshmak K., Giglia A., Nannarone S., Pasquali L.
Physical Review Materials, 2-10, 2018 doi:10.1103/PhysRevMaterials.2.104404

Role of gallium diffusion in the formation of a magnetically dead layer at the Y3Fe5 O12/Gd3Ga5 O12 epitaxial interface

Suturin S.M., Korovin A.M., Bursian V.E., Lutsev L.V., Bourobina V., Yakovlev N.L., Montecchi M., Pasquali L., Ukleev V., Vorobiev A., Devishvili A., Sokolov N.S.
Journal of Chemical Physics, 145-2, 2016 doi:10.1063/1.4956452

Quantitative resonant soft x-ray reflectivity of ultrathin anisotropic organic layers: Simulation and experiment of PTCDA on Au

Capelli R., Mahne N., Koshmak K., Giglia A., Doyle B.P., Mukherjee S., Nannarone S., Pasquali L.
ACS Applied Materials and Interfaces, 7-34:19134-19144, 2015 doi:10.1021/acsami.5b04777

Tuning the Electronic Structure of Graphene by Molecular Dopants: Impact of the Substrate

Christodoulou C., Giannakopoulos A., Ligorio G., Oehzelt M., Timpel M., Niederhausen J., Pasquali L., Giglia A., Parvez K., Müllen K., Beljonne D., Koch N., Nardi M.V.
Langmuir, 31-11:3546-3552, 2015 doi:10.1021/acs.langmuir.5b00177

New one-step thiol functionalization procedure for Ni by self-assembled monolayers

Fontanesi C., Tassinari F., Parenti F., Cohen H., Mondal P.C., Kiran V., Giglia A., Pasquali L., Naaman R.
10960 (2019) doi:10.1117/12.2514998

The hidden energy tail of low energy electrons in EUV lithography

Fallica R., Rezvani S.J., Nannarone S., Borisov S., De Simone D., Babin S., Lorusso G., Vandenberghe G.
Journal of Photopolymer Science and Technology, 32-1:57-66, 2019 doi:10.2494/photopolymer.32.57

Photoresist absorption measurement at extreme ultraviolet (Euv) wavelength by thin film transmission method

Shehzad A., Vesters Y., De Simone D., Pollentier I., Nannarone S., Vandenberghe G., Gendt S.D.